Good developer hygeine

Or use EMACS and its kill ring and multi-level undo (although stock GNU EMACS doesn't put single character deletes into the kill ring).

This could use a better title. Getting from "hygiene" to "clipboard manager" is a stretch.

That said, I use a clipboard manager and find it very convenient. It helps to lessen context changes: I can copy a bunch of stuff onto the cm and then pull it off at the destination. I can copy/cut stuff onto it that I may need at some indefinite point in the future. I don't have to spend time deliberating whether to keep a record of it; if I need it, it's there. I can copy a subsequent item without worrying about losing the current clipboard contents. And I can keep items I occasionally need to reference available in the cm history.

All this works so well because the cm I use has a very quick to use and quick to respond search including limited wildcarding that progressively refines results with each keystroke of the search pattern.